Masteroscillator – a new amateur radio blog

The fantastic thing with both amateur radio and the internet is that you make new good friends all over the globe. A couple of my amateur radio friends have started a new blog with a lot of interesting things, especially when it comes to homebrew equipment. Have a look for yourself!

Numbers Stations, null messages

It is not possible to break the codes and get the meaning of the secret messages of the numbers stations, except for one type of messages. That is when there is nothing to say, a null message. Here are my primitive recordings of four different numbers stations with null messages. Sit back, relax and enjoy!


Spy Numbers Station, Enigma designation: E07

This is a recording that I made with my mobile telephone, (sorry for the inferior quality), of a spy numbers station on shortwave, run by the Russian Intelligence Agency GRU. The station is named E07 by the famous numbers stations monitoring group Enigma. The message, to the spy or agent, is coded and they are probably using so called one-time pads. That is, the key to the codes are only used once and therefore it is not possible to understand the message. OK, but why then are they using plain voice via a shortwave transmitter? After all, this is not the 20th century?

Elementary my dear Watson, It is impossible to trace the recipient this way, contrary to a message sent by regular mail or via the internet! As I have demonstrated by this simple video it is easy to listen to the coded messages even with a small shortwave radio!

For more information regarding this particular spy station:

Radio Sweden, 6065 kHz

Radio Sweden a

Radio Sweden b

In the glory days of international broadcasting, Radio Sweden were pretty prominent, both on 6065 kHz and om medium wave 1178/1179 kHz. In the early 70s there was a popular radio show late Saturday evenings, hosted by Kangaroo Kim and Big Bad Roger. (I think the latter is a professor now.)


HB9CJR, 20 meter CW QRP


HB9CJR front


HB9CJR back

This QSL-card, that arrived just the other day(!), is very special to me:

  • It was from the first and only QSO that I had with my tiny Rock Mite 20 transceiver, from a kit that I assembled myself. (OK I had to send it to Germany once as I didn’t manage to solder a surface-mount IC-circuit properly.) I happened to connect the Rock Mite to a faulty power-supply later and the transceiver was damaged…
  • It was the first, and so far only, QSO where I used paddles.
  • It was the first, and so far only, QSO where I used a output power of less than 1 Watt!
  • I haven’t had any CW-QSO after this one…
  • Last but not least, having a contact with morse telegraphy with this real gentleman, kind and polite in a way you can feel through the dots and dashes!

Sometimes in the future I hope to be able to be active using CW again. Until then

73 de


IBRA Radio

IBRA is a Swedish based religious media company, belonging to the Pentecostal movement, (Pingströrelsen). During the glory days of Shortwave broadcasting they had their own produced programs in Swedish, as well as other languages, and also sold air-time to different evangelistic associations. They used the transmitters of Radio Trans Europe in Portugal. As a teenager I used to make tape recordings of the different programs. I still remember parts of the programs, for instance the last speech by the founder of the Pentecostal movement in Sweden Mr Lewi Pethrus. I also remember recordings with Pastor Jimmie Snow from the Grand Ole Opry, Nashville TN.



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